Sofa



FIG. 1 is a perspective view of a sofa according to this design;

FIG. 2 is a front view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a right side view thereof, the left side being a mirror image thereof. 

CLAIM The ornamental design for a sofa, as shown and described. 